Circuit for tuning oscillators of an electronic musical instrument



June 7, 1960 u. MARKOWITZ 2,939,359

- cmcurr FOR TUNING OSCILLATORS OF AN ELECTRONIC MUSICAL INSTRUMENT Filed March 12, 1958 3 Sheets-Sheet l INVENTOR:

' Q5 LJzrome Markowiig,

FIG. .1;

June 7, 1960 J. MARKOWITZ 2,

cmcum FOR TUNING OSCILLATORS OF AN ELECTRONIC MUSICAL INSTRUMENT Filed March 12, 1958 3 Sheets-Sheet 2 FIG. 5.

INVENTOR:

tferome markowiz'g,

June 7, 1960 J. MARKOWITZ 2,939,359

CIRCUIT FOR TUNING OSGILLATORS OF AN ELECTRONIC MUSICAL INSTRUMENT Filed March 12, 1958 3 Sheets-Sheet 3 TIE-3- Z:

a; INVENTOR:

United States Patent CIRCUIT FOR TUNING OSCILLATORS OF AN ELECTRONIC MUSICAL INSTRUIVIENT Jerome Markowitz, Allentown, Pa., assignor to Allen OrganCompany, Inc., Macungle, Pa., a corporation of Pennsylvania I Filed Mar. 12, 1958, Ser. No. 720,850 16 Claims. (Cl. 84-1.!7)

This invention relates to electronic musical instruments, such as electronic organs and the like, having electronic tube, or transistor typ'e oscillation generators as their main, or ultimate, tone source.

One object of my invention is to provide a novel electronic musical instrument, such for example, as an elec tronic organ, which instrument is adapted to produce all the requisite fundamental, or primary tones of the instrument musical tone range, as well as the other variant tonalitiesand soundeifects that are normally characteristic of, or produceable with, a counterpart constituting non-electronic-musical-instrument, such as a multi-rank pipe organ. I g

The said variant tonalities and sound effects of a multi-rank pipe organ are established, induced, or created, in different ways.v For example, it is well known that theindividual pipes of a pipe organ do not maintain absolute, or perfect, tone pitch and timbre, but are subject to random variations of these tone characteristics and that such variationshave a tendency to impart to a fundamental musical tone a-warm and melodious quality, similar to that present in the human voice and in most, if not all, ordinary musical instruments. Then too, in a multi-rank pipe organ, one pipe rank may be arranged to produce tones that vary to a certain extent from those of another pipe rank to thereby produce a tonality known as a celeste That is to say, such a tone variant involves the use of two ranks of pipes, one of which is usually tunedslightly sharp to the other. While many different types of .tonalities can be combined to produce a celeste, the more-common. practice is to combine the tonalitiesof the same type tone producing elements. For example, if a flute celeste is desired, two ranks. of flute tones are combined, one of which is tuned slightly sharp to the other. If a string celeste is desired, two ranks of string tones are combined, one of which is tuned slightly sharp relative to the. other, and so on. When theceleste stopof a pipe organ is drawn and a key of the keyboard thereof is-then'depressed, two pipes that are relately tuned as indicated, are caused to sound a celeste tonality. Since sucha tonality includes the characteristic undulation or beat of a celeste tonality, its effect is highlydesirable in the rendition, or playing, of many types of musical literature. I

The simulation or production of such indicated variant tonali-ties and sound effects has heretofore been achieved, to a certain extent, with electronic musical instruments which embody relatively complex and costly equipment that requires considerable mounting space.

Another object of my invention is to provide an electronic musical instrument of the type indicated, having 1 novel means adapted to produce all the said requisite fundamental tones, variant tonalities and sound effects and which means is much less costly, structurally simpler and requires less mounting space, than the similar means of the prior art electronic'musical instruments.

A further object is to provide such an electronic musical instrument which has certain structural, functional,

2,939,359 Patented June 7, 1960 ICC as well as variant tonality producing features of advantage over the similar instruments of the prior art.

An additional object is to provide such an electronic musical instrument in which the operative actuation of each individualplaying, key can cause, in selectively determined manner, the sounding of one of the fundamental tones of the instrument tone range, or the said tone modified to the extent of including a celeste, pitch fringe, pitch variation, pitch fringe indefiniteness, or some other determinedly established tone variant of this general order.

It is also an object to provide an electronic organ type musical instrument having two or more separate audio systems, the loudspeakers of which are so arranged relative to each other that the said celeste, pitch fringe, pitch variation; pitch fringe indefiniteness, or other determinedly established tone variant of this general order produced.- in accordance with my invention, with be emitted from the separate loudspeakers of said audio systems in the binaural, trinaural, or stereophonic sound effect producing manner, characteristic of the spatial tone distribution pattern effect produced by a multi-rank pipe organ arrangement.

Another object is to provide such an electronic musical instrument having a single-rank electronic tone oscillation generator arrangement and novel means for utilizing a half-tone above, or below, any note of the musical scale produced by the individual generators, as a source of the celeste, pitch fringe, pitch variation, pitch fringe indefiniteness, 'or other determinedly established tone variant of this general order.

Another object is to provide such an electronic musical instrument having playing keys of the single contact type, whereby the various indicated tonality results can all be accomplished with a structurally simple arrangement of single-contact key control elements for each note pitch.

Other objects are, to provide in an electronic musical instrument, such as an electronic organ having a singlerank electronic tone oscillation generator arrangement of either the electronic tube, or the transistor type, a keyboard, sound producing means to which the audio outputs of the generators are connected, and a circuit system for operatively connecting each of the keys of the keyboard with one of the tone oscillation generators; of one or more unique elements, or features, such as means in said circuit system whereby each of the respective keys of the keyboard is also operatively connected to a second and/or third tone oscillation generator so that operative actuation of each'individual key will cause simultaneous operation of two or three of the tone oscillation generators to produce oscillations that effect a fundamental tone of the musical tone scale and the other one of said oscillation generators to produce oscillations which elfect a half-tone higher, or lower, than said fundamental tone; a series inductance capacity arrangement in said circuit system which causes the frequency of the higher or lower half-tone producing oscillations to come substantially closer to the frequency of the fundamental tone producing oscillations, so that the resultant musical sound constitutes a determinedly established variant of said fundamental tone; diode means in said circuit system adapted to prevent reverse keying; and means connecting the audio outputs of the single-rank oscillation generators so as to either form a two-tone system involving two trunk lines, one of which has connected therewith generators 1, '3, 5, etc. and the other trunk line has connected therewith generators 2, 4, 6, etc., or to form a triple-tone system involving three trunk lines, the first of which has connected therewith generators 1, 4, 7, etc., the second of which has connected therewith generators 2, 5, 8, etc., and the third of which has connected therewith generators 3, 6, 9, etc., the two trunk lines of the two-tone system being connected with two separate audioamplifier systems and the three trunk lines of the tripletone system being connected with three separate audioamplifier systems, whereby the loudspeakers of the said respective twoor three-tone systems can be relatively spaced in such manner as to effect a true binaural, trinaural, stereophonic, or spatial effect, even when singlenote melody lines are played. 7

Another object of this invention is to provide an electronic musical instrument of the type' indicated which provides a multi-rank tonal effect from a single rank of oscillators in which all oscillators operate at a single direct current operating potential, thereby greatly simplifying the wiring of the keyboards.

With these and other objects in view, which will become more readily apparent from the following detailed description of the various practical and illustrative embodiments of the novel developments shown in the accompanying drawings, my invention comprises the new electronic musical instrument, elements, features of construction and arrangement of parts in cooperative relationship, as more particularly indicated and defined by the hereto appended claims. I

In the accompanying drawings:

Figure 1 is a diagrammatic, or schematic illustration of a certain portion of an electronic organ system embodying my invention, which organ system includes a single-rank electronic tube type tone oscillation generator arrangement.

Fig. 2 is an illustration, similar to Fig. 1, and discloses an electronic organ system portion that includes a singlerank transistor type tone oscillation generator arrangement. 2

Fig. 3 is an illustration, similarto Fig. l and shows another form of electronic organ system in accordance with my invention that is provided with a plurality of separate, or independent, audio units for producing the binaural or trinaural sound effect previously mentioned.

For purposes of exemplification, or illustration, my invention is herein disclosed as embodied in, or forming part of a standard, or conventional type electronic organ system having a single-rank electronic tone oscillation generator arrangement. However, only those parts of such a complete organ system are shown in the drawings as will facilitate an understanding of the construction and operation of my invention, the performance of its intended purpose and the manner in which it achieves certain unique and desirable results and advantages. In this connection it is, of course, to be understood that the electronic organ system here involved includes, in cooperative combination with the various elements of my invention, all those usual standard or conventional parts, which make such an electronic organ system complete and operative in the usual and well-known manner of the prior art electronic organ practice. From this disclosure it will be readily apparent to those skilled in this art how my invention can be utilized to accomplish substantially the same advantageous results, with other types of electronic musical instruments.

As previously indicated, the embodiment of my invention in an electronic musical instrument attains certain desirable, beneficial and advantageous results, such as reduced production cost, structural and functional simplification, economy in required electrical equipment and mounting space therefor, etc. This will become more apparent by comparison of the invention with the various prior art patents which disclose similar electronic musical instruments of the type heretofore available and which, by substantially more involved and complex means,-

accomplish somewhat similar tonality results of the type here involved. For example, comparison can be made for this purpose with the disclosure of U.S. Hanert Patent No. 2,681,585, which was issued June 22, 1954, after the following detailed description of the drawing disclosure of my invention is clearly understood.

Referring now to the accompanying drawings, in which similar reference characters designate corresponding parts, Fig. 1 diagrammatically illustrates one form of circuit system and equipment means arranged to provide an electronic musical instrument, or organ, in accordance with my invention. In this arrangement, well known Hartley type fundamental tone producing oscillators, or oscillation generators, are provided for each musical tone frequency and the total number of such tone oscillators is, of course, determined by the tone range of the instrument or organ. For purposes of simplification of disclosure, only three of such fundamental tone producing oscillators are shown arranged in single-rank manner for producing the organ notes C, Cit and D of one musical octave of the organ tone range.

In general, the circuit system of Fig. 1 comprises a series of standard electronic tubes, or triodes, that are respectively designated 1, 1 and 1 and a correspond ing series of single-contact organ playing, or circuit control keys, that are respectively designated 2, 2 and 2 The triodes 1, 1 and 1 are alike and each consists of a cathode 3, a control grid 4 and a plate 5. The cathode 3 is, in each instance, connected to ground through a conductor 6, a portion of an inductor coil 7 and conductor 8.

The inductor coil 7 has connected therewith in parallel a capacitor 9, as established by common terminals 10 and 11, and the control grid 3 is connected to the terminal 11 through a capacitance-resistor unit 12. The common terminal Not the tank components 7 and 9 is connected to ground by the conductor 8. By this arrangement, the frequency of the tone oscillations of the triodes 1, 1 and 1 is established by the said tank components consisting of the inductor coil 7 and the capacitor 9.

A source of electrical energy, indicated by the electrical battery symbol 13, has its positive terminal connected at 14 to a common line, or bus 15 and the latter in turn is connected with one terminal of each of the single-contact series keys 2, 2 and 2 The negative terminal of the source of electrical energy 13 is connected to ground by a wire 16.

When a respective key 2, 2 2*, etc. of the series keys is operatively actuated, depressed, or closed, current flow will take place through a conductor 17 to the plate 5 of a respective series corresponding triode 1, 1 1 etc. through a resistor 18 and diode 19, thereby causing a respective triode and its described associated parts to function in usual and well known manner to effect the fundamental tone producing oscillations of the musical scale notes, C, Cit, D, etc. of the tone range of the instrument, or organ.

The outputs of the respective oscillators, or oscillator generators, are respectively caused to flow through an isolation resistor 20 to a common bus or trunk line 21, which is connected by a conductor 22 with a conventional type audio amplifier unit 23 that provides the required gain or drive for a loudspeaker 24.

Single pole switches 25 are provided in the circuit system that form part of a ganged switch arrangement adapted to be unitedly actuated by a stop tablet (not shown) at the organ console (not shown). Actuation of said stop tablet in selective manner will cause an element indicated by the numeral 26 to combinedly effect movement of a series of switch control elements 27, so as to simultaneously open or close all the switches 25, as selec-v When the switches'25 are open and the respective series keys 2, 2, 2", etc. are operatively actuated in individual manner, each oscillator that includes one of the series corresponding triodes 1, 1, 1', etc. will be individually operated, with the result that the'loudspeaker 24 will emit, in each instance, a fundamental musical tone corresponding with one of the notes C, Cit, D, etc. of the musical tone scale range of the instrument. In other words, when the switches 25 areopen' and the series keys 2, 2, 2', etc. are'operatively actuated current How will take place from the battery 13,.through a respective series key to the plate 5 of respective'series triode 1,1,1", etc. so as to cau'se'the oscillation generator, of which said respective series triode forms" a part, to become energized and consequently causethe loudspeaker 24 to emit the fundamental musical tone of: said 'oscillation' generator.

On the other hand, when the switches 25 are closed, operative actuation of a respective series key will not only cause current flow to take place as just described, but current flow will also occur in the adjacent oscillator of relatively next higher frequency, through a respective diode 33 and respective inductor 3'1,.-and then through the plate circuit of said relatively next higher frequency oscillator. However,.plate current fiowthrough' the selectively adjustable inductor 31 of said relatively next higher frequency oscillator can be regulated so as to result in substantially lowering the normal frequency produced by the tank circuit 7 and 9 components of said relatively next higher frequency oscillator, so that the tone frequency produced by the latter closely approaches the normal tone frequency produced by the oscillator that effects the relatively lower fundamental tone. This lowered tone frequency produced by the oscillator of the higher half-tone circuit, depending upon its determined extent of variation from the oscillation frequency of the fundamental tone, manifests itself in the form of a celeste, pitch fringe, pitch variation, pitch fringe indefiniteness, or other determinedly established-tone variant of this general order, when emitted as a tonal effect from the loudspeaker 24 in conjunction with the fundamental tone.

To further illustrate this, let it be assumed that the series key 2 is operatively actuated to cause the loudspeaker 24 to emit the Cl? tone and that the switches 25 are closed. The circuit arrangement will then be energized which will cause the Cit oscillation generator to oscillate at its normal frequency, as established by its respective tank circuit 7 and 9 components and, at the same time, the circuit arrangement will be energized which will cause the relatively next higher half-tone D oscillator to, oscillate at a frequency slightly higher than Cit, that is to say, to a higher extent as precisely dertermined by selective adjustment of the inductor 31 in the plate circuit of the triode -1. While this is taking place, the lower frequency oscillator that produces the note C will be prevented from operating due to the current flow blocking action of the respective diode 33 that prevents current flow from the series key 2 to the plate 5 of the triode 1. In this connection it is to be noted that the resistor 18 in series circuit with the adjacent diode 19 that connects with the plate 5 of the Cit oscillation generator is provided to establish a satisfactory balance or equivalent intensity when the adjacent oscillation generator is functioning that producesthe note, or tone D frequency, in its modified form as explained.

Accordingly, in the form of my invention illustrated by Fig. 1, when the switches 25 are openand the series keys 2, 2, 2-", etc. of the musical instrument are individually closed, this will effect the operation, in each instance, of a single oscillator circuit arrangement, so that each respective series key will. cause only the production of a fundamental tone of the musical tone range scale of the electronic. instrument, or organ. However, when the switches 25 are closed, each series key 2, 252 etc. will effect energization of two adjacentoscillator circuit ar- Iangem'ents, whereby operative actuation of a respective series key will effect the production of afundamental tone in conjunction with a pitch fringe variation added to said fundamental tone by determined lowering of the frequency of the next higherhalf-tone producing oscillator of the second circuit arrangement that is energized. In this connection, the oscillator of the relatively next lower half-tone to said fundamental tone is prevented from operating by the current flow blocking action of diod means.

Fig. 2 ofthe drawings diagrammatically illustrates another form of circuit system and means arranged to provide an electronic musical instrument, or organ, in accordance. with my invention. In general, this embodiment of my invention diifers from the embodiment of my invention shown in Fig. 1 only in that standard type transistors T, T T etc. are substituted for the standard triode electronic tubes 1, 1*, =1, etc. of Fig. l and in that certain correspondingly required simplechanges, or additions, have been made in the circuit system of Fig. 2, in order that the same functional and tonality results are accomplished by the Fig. 2 embodiment of my invention as are accomplished by the Fig. 1 embodiment thereof. Since there is substantial correspondence of the electrical elements and circuits between Fig. 2 with Fig. 1, redundancy of descriptive matter will be avoided by the correspond ing identification of those elements of Fig. 2 shown in Fig. 1 which have already been described.

The said simple required changes, or additions, consist in the substitution of a capacitor 36 for the capacitance-resistor unit 12. of Fig. 1; the provision of a resistor 37, one terminal of which is connected between the capacitor 36 and one terminal of a respective transistor, and the other terminal of which is connected to ground and to inductor coil 7; and in the provision of a resistor 38 having one terminal thereof connected by a conductor 38 with a terminal of the transistor, and another terminal thereof connected by a conductor 39 with the terminal 10 of the tank components 7 and 9.

It will be understood that in the Fig. 2 embodiment of my invention, the conductor connections made to the transistors T, T and T correspond equivalently with those made to the triodes of the Fig. 1 embodiment of my invention, since in each instance there are three connecting terminals involved.

Fig. 3 of the drawings discloses another modified form of circuit system and equipment means arranged to provide an electronic musical instrument, or organ, in accordance with my invention. Here again, for simplification of illustration, a single rank of standard electronic rectifier tubes, or triodes, are shown along with a corresponding series of single-contact playing, or circuit control keys, which in this instance are shown grouped together.

In general, the circuit system of Fig. 3 is similar, to a certain extent, to that disclosed by Fig. 1, in that the same well known Hartley type fundamental tone producing oscillators, or oscillation generators, are provided for each musical tone frequency and the total number of such tone oscillators is again determined by the tone range of the instrument, or organ. In Fig. 3, six such fundamental tone producing oscillators are shown arranged in singlerank, or series manner, for producing the organ notes C, Ct D, Dtl, E and F, of one musical octave of the organ tone range. The standard electronic tubes, or

triodes, of the oscillators for producing the said organ like those shown in Fig. l, such'elements or parts have been identified in Fig. 3 by reference characters corresponding with those of Fig. 1, to thereby avoid redundancy It is to be understood thatthe of descriptive matter.

said correspondingly identified elements or parts of Fig. 3 are structurally and functionally the same as those shown and described in connection with Fig. 1 and that such parts serve the same purpose in each instance. It is also to be understood that, if desired, the switches 25 of Fig. 1, together with the gang switch operating means therefor, as indicated by the numerals 26 and 27 in Fig. 1 can be included in the Fig. 3 embodiment of my inventron.

The features of difference which exist in the circuit system of Fig. 3, over that disclosed by Fig. l, are generally as follows:

The oscillators in Fig. 3 have their isolating resistors 20 connected to three audio trunk or bus lines 52, 53 and 54, so that the 1st, 4th, 7th and so on of the series of oscillators are connected to the bus line -2, the 2nd, 5th, 8th and so on of the series of oscillators are connected to the bus line 53, and the 3rd, 6th, 9th and so on of the series of oscillators are connected to the bus line 54. The bus line 52 is connected by a conductor 55 to a conventional type audio amplifier unit 56 that provides the required gain or drive for a standard loudspeaker 57. Likewise, the bus line 53 is connected by a conductor 58 with a conventional type audio amplifier unit 59 that provides the drive for a standard loudspeaker 60. A conductor 61 similarly connects the bus line 54 with a conventional type audio amplifier unit 62. that provides the required drive for a standard loudspeaker 63.

The single-contact keys 46, 47, 48, 49, 50 and 51 are respectively connected, as in Fig. 1, with one terminal of a resistor 18 by conductors designated 64, 65, 66, 67, 68 and 69, so that, when one of said keys is operatively actuated, current flow will take place to the plate 5 of a respective series corresponding triode 40, 41, 42, 43, 44 or 45, through the resistor 18 and a diode 19, thereby causing a respective triode and its associated parts to function as described in connection with Fig. 1, so as to effect the fundamental tone producing oscillations of the musical scale notes C, Cit, D, Dit, E and F.

To make clear certain further differences between the embodiment of my invention disclosed by Fig. 3, as compared with the embodiment of Fig. 1, let it be assumed that a respective key is operatively actuated, say, for example the key 48, so as to effect direct operation of the oscillator that produces the fundamental D tone, by current flow from the positive terminal of the battery 13-, through key 48, conductor 66, through a resistor 18, a diode 19 to the plate 5 of the triode 42, then the circuit system of Fig. 3 will also cause the two oscillators that are directly adjacent to the D tone producing oscillator to simultaneously operate with the latter. That is to say, the Cit tone producing oscillator will effect oscillations that in frequency are slightly lower by a few cycles than those of the D tone producing oscillator, while the Dil tone producing oscillator will effect oscillations that in frequency are slightly higher by a few cycles than those of the D tone producing oscillator. The oscillation of the Cl? oscillator results when current flow occurs from the energized conductor 66, through a conductor 70, a diode 71, a conductor 72, a selectively adjustable inductor and capacitance unit 73, a conductor 74, that connects at 75 with the conductor leading to the plate 5 of the triode 41. The unit 73 is selectively adjusted so as to produce a Cit oscillator frequency that will be higher than the normal Cf frequency to a degree substantially approaching the normal frequency of the D tone producing oscillator and to an extent that will add to the fundamental D tone a lower pitch fringe sound effect, or pitch fringe variation, etc., as selectively determined by adjustment of said unit 73.

The oscillation of-the Dit oscillator results when current flow occurs from the energized conductor 66, through a conductor 76, a selectively adjustable inductor 77, a conductor 78, a diode 79, a conductor 80 that connects at 81 with the conductor leading to the plate 5 of the triode 43. The inductor 77 is selectively adjusted so as to produce a D1 oscillator frequency that will be lower than the normal Dtf frequency to a degreesubstantially approaching the normal frequency of the D tone producing oscillator and to an extent that will add to the fundamental D tone a higher pitch fringe sound effect, pitch fringe variation, etc., as selectively determined by adjustment of said inductor 77.

Accordingly, when the organ key 48 is depressed, or operatively actuated, the three circuit arrangements that include the Cit, D and Di? tone oscillators are simultaneously energized and produce a combined tonality effect, as explained, and the musical sound produced by each of said circuit arrangements is fed to the three in dependent audio amplifying units 56, 59 and 62, as pre viously explained.

The loudspeakers 57, 60 and 63 are spaced relative to each other in such manner that the said resultant tonality combination effectris one in which a fundamental tone is heard that is modified byv two independent pitch fringe supplementations and a stereophonic, or trinaural quality.

It is to be noted that when this three circuit arrangement is energized as above explained, current flow in reverse direction through a respective selectively adjustable inductor 77 is prevented by the diode 79 that is in series connection therewith. This is likewise true of the respective selectively adjustable inductor-capacitance units 73 that have a diode 71 in series connection therewith.

As indicated by Fig. 3, the said three circuit arrangement is repeated, or duplicated, throughout the entire single-rank oscillator circuit system, so that operative actuation of each playing key will accomplish the same result with respect to each fundamental tone of the entire tone range of the musical instrument or organ.

It has been previously stated that single-contact key control elements are employed for each note pitch. It should beunderstood that this type of structure is shown mainly for the purpose of illustration so as to clearly indicate an important difference between this invention and the prior art. The prior art discloses multi-contacts which operate in conjunction with each key to obtain results approaching, to a certain extent, those of the present invention. The construction of a truly organistic instrument usually involves the playing of several notes or pitches from a single key, however, the incorporation of such arrangements and couplers are well-known to anyone acquainted with organ building and, therefore, need not be entered into in this disclosure. The important point is that the single contact for each note pitch enables the advantages of this invention to be achieved with a simple wiring arrangement similar to that employed in pipe organs.

It should also be observed that the two-circuit arrangement of Figure 1 shows a given key operating its corresponding fundamenfal pitch oscillator and also, the next higher half-tone. It is also feasible to employe next lower half-tone as the associated tone for the fundamental as shown in Fig. 3. The selection of the next higher half-tone arrangement of Figure l is merely a matter of choice.

As previously indicated, comparison of my novel electronic musical instrument circuit system and the component elements thereof with the similar systems and elements of the prior art will disclose that my invention attains such desirable and beneficial advantages as reduced production cost, structural and functional simplification, economy in required electrical equipment and mounting space therefor, etc.

'Therefore, to my knowledge, the present invention represents the first electronic musical instrument system for producing the positive musical advantages of independent celeste, pitch fringe, pitch variation, pitch fringe indefiniteness, or other determinedly established tone" variants of this general order, together with binaural, trinaural or stereophonic quality, for each fundamental assassin tone ofthe musical tone scale, without the use ofspecial; or additional oscillation generators and with allkeying circuits operating at a common direct current potential, so that the most elementary type single-contact key elements can be employed. To my knowledge, the present invention is also unique in that the control wiring is not directly connected with the tuning circuits so that extended length keying cables can be used. This is of distinct advantage in the more complex, or more-comprehensive type musical instruments, involving a multiplicity of oscillation generators and oscillator current equipment that ordinarily occupies a volume ofspace toolarge to be installed in the organ console.

Finally, it is to be noted that no musical compromise is involved in the practice of' my invention. and that distinct musical advantages can-.be'den'ved from its use along with the indicated economy features.

From the foregoing it willbe readily apparent to those skilled in this art that the electronic musical instrument improvements specifically shown and described can be changed and modified in various ways without departing from the inventionherein disclosed, the scope of which is more particularly indicated-and defined by the hereto appended claims;

I claim:

1. In an electronic musical instrument having a series of oscillation generators for producing the consecutive fundamental tones of the musical tone scale, a corre-' sponding seriesof operating keys each having a' single operating contact forqeach consecutive fundamental toneoscillation generator, and means for converting the out puts of said oscillation generators into musical sound; of a circuit system which comprises a double circuit arrangement that is controlled by the single operating con tact of a certain one ofsaid keys in such manner that the first circuit arrangement establishes an operative connection between said certain one of said keys and its series corresponding fundamental tone producing oscillation generator, and the second circuit arrangement establishes an operative connection between said certain one of said keys and a second oscillation generator that produces the consecutively next higher half-tone, the said second circuit arrangement including series inductance means for causing the frequency of the consecutively next higher half-tone producing oscillation generator to drop substantially closer to the frequency of the first circuit fundamental tone producing oscillation generator, and said second circuit arrangementalso including diode means which functions to prevent the fundamental tone producing oscillation generator of said first circuit from operating when the series key for the consecutively next higher half tone producing oscillation generator of the second circuit arrangement is operatively actuated.

2. In an electronic musical instrument having a series of oscillation generators for producing the fundamental tones of the musical tone scale, and means for converting the outputs of said oscillation generators into musical sound; of twosingle-contact keys for respectively operating a fundamental tone and a relatively next higher halftone producing oscillation generator; and a circuit system which comprises a first single=contact key controlled double circuit arrangement of which one circuit arrangement is adapted to establish an operative connection between the first single-contact operating key and the fundamental tone producing oscillation generator, and the second circuit arrangement is adapted to establish anoperative connection between said first single-contact operating key and the relatively next higher half-tone, the said second circuit arrangement including series inductance means for causing the frequency of the normally higher half-tone producing oscillation generator to drop substantially closer to the frequency of that normally associated with the fundamental tone producing oscillation generator, and said second circuit arrangement also including diode means which functions to prevent the fundamental tone producing oscillation generator from operating when the second single-contact key is operatively actuated to-elfect independent normal operation of the half-tone producing oscillation generator.

3. In an electronic musical instrument having a series of oscillation generators for producing the fundamental tones-of the instrument tone-range, a corresponding series of operating keys, and means for converting the outputs of said oscillation generators into musical sound; of a circuit system which comprises a plurality of similar single series key controlledtwo circuit arrangements of which one circuit arrangement is adapted to establish an operative connection between a respective series key and its series-corresponding fundamental tone producing oscillation generator, and the second circuit arrangement is adapted to establish an operative connection between said respective serieskey and a second oscillation generator that produces a relatively next higher half-tone, the said second circuit arrangement including series inductance means for causing the frequency of the normally higher half=tone producing oscillation generator to drop substantially'closer to the frequency of that normally associated with the fundamental tone producing oscillation generator, and said second circuit arrangement also including diode means which functions to prevent the lower pitched tone producing oscillation generator from operating when the series key for the higher tone producing oscillation generator is operatively actuated.

4. In an electronic musical instrument having a series of oscillation generators for producing the fundamental tones of the instrument tone range, and means for converting the outputs of said oscillation generators into musical sound; of a series of single-contact operating keys which in number equal the number of said oscillation generators; and a circuit system which comprises similar single key controlled two circuit arrangements of which one circuit isadapted to establish an operative connection between a' respective series key and its series corresponding fundamental tone producing oscillation generator, and the second circuit arrangement is adapted to establish an operative connection between said respective series key and a second oscillation generator that produces a relatively next higher half-tone, the said second circuit arrangement including series inductance means for causing the frequency of the normally higher half-tone producing oscillation generator to drop substantially closer to the frequency of that normally associated with the fundamental tone producing oscillation generator, and said second circuit arrangement also including diode means which functions to prevent the lower pitched tone producing oscillation generator from operating when the series key for the higher tone producing oscillation generator is operatively actuated.

5. In an electronic musical instrument having a series of oscillation generators for producing the fundamental tones of the musical tone scale, a corresponding series of operating keys, and means for converting the outputs of said oscillation generators into musical sound; of a circuit system which comprises a single key controlled triple circuit arrangement of which one circuit arrangement is adapted to establish an operative connection between a certain series 'key and its series corresponding fundamental tone producing oscillation generator, the second circuit arrangement is adapted to establish an operative connection between said certain series key and a second oscillation generator that produces a relatively next lower half-tone, the said second circuit arrangement including series inductance and capacitance means for causing the frequency of the normally lower half-tone producing oscillation generator to increase substantially so as to come closer to the frequency of that normally associated with the fundamental tone producing oscillation generator, and said second circuit arrangement also including diode means which functions to prevent the fundamental tone producing oscillation generator" fromoperating when the series key for the lower half-tone producing oscillation generator is operatively actuated, and said third circuit arrangement is adapted to establish an operative connection between said certain series key and a third oscillation generator that produces a relatively next higher half-tone, the said third circuit arrangement including series inductance means for causing the frequency of the normally higher half-tone producing oscillation generator to drop substantially closer to the frequency of that normally associated with the fundamental tone producing oscillation generator, and said third circuit arrangement also including diode means which functions to prevent the fundamental tone producing oscillation generator from operating when the series key for the higher half-tone producing oscillation generator is operatively actuated.

6. In an electronic musical instrument having a series of oscillation generators for producing the fundamental tones of the instrument tone range, and means for converting the outputs of said oscillation generators into musical sound; of a series of single-contact operating keys which in number equal the number of said oscillation generators; a circuit system which comprises a plurality of similar single series key controlled triple circuit arrangements of which one circuit arrangement is adapted to establish an operative connection between a respective series key and its series corresponding fundamental tone producing oscillation generator, the second circuit arrangement is adapted to establish an operative connection between said respective series key and a second oscillation generator that produces a relatively next lower half-tone, the said second circuit arrangement including series inductance and capacitance means for causing the frequency of the normally lower half-tone producing oscillation generator to increase so as to come substantially closer to the frequency of that normally associated with the fundamental tone producing oscillation generator, and said second circuit arrangement also including diode means which functions to prevent the fundamental tone producing oscillation generator from operating when the series key for the lower half-tone producing oscillation generator is operatively actuated, and said third circuit arrangement is adapted to establish an operative connection between said respective series key and a third oscillation generator that produces a relatively next higher half-tone, the said third circuit arrangement including series inductance means for causing the frequency of the normally higher half-tone producing oscillation generator to drop substantially closer to the frequency of that normally associated with the fundamental tone producing oscillation generator, and said third circuit arrangement also including diode means which functions to prevent the fundamental tone producing oscillation generator from operating when the series key for the higher half-tone producing oscillation generator is operatively actuated.

7. In an electronic musical instrument having operating keys and a series of fundamental electronic tube oscillation generators in a number equal to the number of keys; of means for operatively connecting each key to its corre sponding oscillation generator; means for operatively connecting each key, also, to each oscillation generator that produces its next higher half-tone, which latter means includes a series inductance that causes the frequency of the normally higher half-tone to drop substantially closer to the frequency of that normally associated with the fundamental and which latter means also includes a diode that prevents the lower pitched tone from sounding when the higher note key is depressed; and means for converting the audio outputs of the oscillation generators into musical sound.

8. In an electronic musical instrument having operating keys and a series of fundamental transistor type oscillation generators in a number equal to the number of keys; of means for operatively connecting each key to its corresponding oscillation generator; means for operatively connecting each key, also, to each oscillation generator that produces its next higher half-tone, which latter means includes a series inductance that causes the frequency of the normally higher half-tone to drop substantially closer to the frequency of that normally associated with the fundamental and which latter means also includes a diode that prevents the lower pitched tone from sounding when the higher note key is depressed; and means for converting the audio outputs of the oscillation generators into musical sound.

9. In an electronic musical instrument having a series of operating keys and a corresponding series of electronic tube oscillation generators for producing the fundamental tones of the musical tone scale; of means for operatively connecting each key with its corresponding oscillation generator; means for operatively connecting each key, also, to each oscillation generator that produces its next higher half-tone, which latter means includes a series inductance that causes the frequency of the normally higher half-tone to drop substantially closer to the frequency of that normally associated with the fundamental tone, and which latter means also includes a diode that functions to prevent the lower pitched tone producing generator from functioning when the higher note key is operatively actuated; an audio system including a loudspeaker and a conductor that is connected with the audio outputs of the oscillation generators that effect the tones of the first, third and higher odd number of notes of the series of oscillation generators; a second audio system including a loudspeaker and a conductor that is connected with the audio outputs of the oscillation generators that effect the tones of the second, fourth and higher even number of notes of the series of oscillation generators; the loudspeakers of the first and second audio systems being spacedly arranged relative to each other in such manner that individual operative actuation of said keys will cause said loudspeakers to combinedly emit a tone that has an independent pitch fringe and stereophonic quality.

10. In an electronic organ having a series of operating keys, a corresponding series of fundamental tone producing oscillation generators, means operatively connecting each key and corresponding oscillation generator, and means for converting the audio outputs of the oscillation generators into musical sound; of a circuit arrangement for connecting each key, also, to an oscillation generator that produces its next higher half-tone, which circuit arrangement includes inductance means that causes the frequency of the normally higher half-tone producing oscillation generator to drop substantially closer to the frequency of that normally associated with the fundamental tone producing oscillation generator, and which circuit arrangement also includes diode means that functions to prevent the lower pitched tone producing oscillation generator from operating when the key for the higher tone producing oscillation generator is operatively actuated.

11. In an electronic musical instrument having a series of oscillation generators for producing the fundamental tones of the instrument tone range; of a series of singlecontact operating keys which in number equal the number of said oscillation generators; a circuit system which comprises similar single-key controlled two circuit arrangements of which one circuit is adapted to establish an operative connection between a respective series key and its series corresponding fundamental tone producing oscillation generator, and the second circuit arrangement is adapted to establish an operative connection between said respective series key and a second oscillation generator that produces a relatively next higher half-tone, the said second circuit arrangement including series inductance means for causing the frequency of the normally higher half-tone producing oscillation generator to drop substantially closer to the frequency of that normally associated with the fundamental tone Producing oscillation generator,

13 and said second circuit arrangement also including diode means which functions to prevent the lower pitched tone producing oscillation generator from operating when the series key for the higher tone producing oscillation generator is operatively actuated; an audio system including a loudspeaker and a conductor that is connected with the audio outputs of the oscillation generators that effect the first, third and higher odd number of notes of the series of oscillation generators a second audio system including a loudspeaker and a conductor that is connected with the outputs of the oscillation generators that effect the tones of the second, fourth and higher even number of notes of the series of oscillation generators; the loudspeakers of said audio systems being spacedly arranged relative to each other in such manner that individual operative actuation of said keys will cause said loudspeakers to combinedly emit a tone that has an independent pitch fringe and stereophonic quality.

12. In an electronic musical instrument having a series of oscillation generators for producing the fundamental tones of the instrument range; of a series of single-contact operating keys which in number equal the number of said oscillation generators; a circuit system which comprises similar single-key controlled triple circuit arrangements of which one circuit arrangement is adapted to establish an operative connection between a certain series key and its series corresponding fundamental tone producing oscillation generator, the second circuit arrangement is adapted to establish an operative connection between said certain series key and a second oscillation generator that produces a relatively next lower half-tone, the said second circuit arrangement including series inductance and capacitance means for causing the frequency of the normally lower half-tone producing oscillation generator to increase substantially so as to come closer to the frequency of that normally associated with the fundamental tone producing oscillation generator, and said second circuit arrangement also including diode means which functions to prevents the fundamental tone producing oscillation generator from operating when the series key for the lower half-tone producing oscillation generator is operatively actuated, and said third circuit arrangement is adapted to establish an operative connection between said certain series key and a third oscillation generator that produces a relatively next higher half-tone, the said third circuit arrangement including series inductance means for causing the frequency of the normally higher half-tone producing oscillation generator to drop substantially closer to the frequency of that normally associated with the fundamental tone producing oscillation generator, and said third circuit arrangement also including diode means which functions to prevent the fundamental tone producing oscillation generator from operating when the series key for the higher half-tone producing oscillation generator is operatively actuated; an audio system including a loudspeaker and a conductor that is connected with the audio outputs of the oscillation generators that effect the first, fourth, seventh, tenth and so on continuing sequence of the series of oscillation generators; a second audio system including a loudspeaker and a conductor that is connected with the audio outputs of the oscillation generators that effect the second, fifth, eighth, eleventh and so on continuing sequence of the series of oscillation generators; and a third audio system including a loudspeaker and conductor that is connected with the oscillation generators that effect the third, sixth, ninth, twelfth and so on continuing sequence of the series of oscillation generators; the loudspeakers of said audio systems being spacedly arranged relative to each other in such manner that individual operative actuation of said keys will cause said loudspeakers to combinedly emit a tone that has independent pitch fringe and stereophonic qualities.

13. In an electronic musical instrument having operating keys and a series of fundamental electronic tube oscillation generators in a number equal to the number of keys; of means for operatively connecting each key to its corresponding oscillation generator; means for operatively connecting each key, also to an adjacent oscillation generator, said means including a series inductance so as to cause the frequency of the adjacent oscillation generator to approach that of the fundamental generator; which means also includes a diode that prevents the fundamental note from operating when an adjacent oscillator key is depressed; and means for converting the audio outputs of the oscillation generators into musical sound.

14. In an electronic musical instrument having a series of oscillation generators for selectively producing the consecutive fundamental tones of the instrument tone range; of a series of individual oscillation generator operating keys each having a single operating contact for each consecutive fundamental tone oscillation generator; means for pitch modifying the tones produced by said oscillation generators; circuit means for simultaneously effecting the operation of three determined oscillation generators which individually produce a certain fundamental tone, a pitch modified consecutively next higher tone and a pitch modified consecutively next lower tone when one of said keys is operatively actuated; and three audio systems connected with said circuit means in such manner that each of the said three determined consecutive tone producing oscillation generators will speak through only one of said audio systems.

15 In an electronic musical instrument having a series of oscillation generators for selectively producing the consecutive fundamental tones of the instrument tone range; of a series of individual oscillation generator operating keys each having a single operating contact for each consecutive fundamental tone oscillation generator; means for pitch modifying the tones produced by said oscillation generators; circuit means for simultaneously effecting the operation of two determined oscillation generators which individually produce a certain fundamental tone and a pitch modified consecutively next higher tone when one of said keys is operatively actuated; and two audio systems connected with said circuit means in such manner that each of said two determined consecutive tone producing oscillation generators will speak through only one of said audio systems.

16. In an electronic musical instrument having a series of oscillation generators for selectively producing the consecutive fundamental tones of the instrument tone range; of a series of individual oscillation generator operating keys each having a single operating contact for each consecutive fundamental tone oscillation generator; means for pitch modifying the tones produced by said oscillation generators; circuit means for simultaneously effecting the operation of two determined oscillation generators which individually produce a certain fundamental tone and a pitch modified consecutively next lower tone when one of said keys is operatively actuated; and two audio systems connected with said circuit means in such-manner that each of said two determined consecutive tone producing oscillation generators will speak through only one of said audio systems.

References Cited in the file of this patent UNITED STATES PATENTS Re. 21,137 Firestone July 4, 1939 2,579,358 Bourn Dec. 18, 1951 2,662,148 Stibitz Dec. 8, 1953 2,800,047 Hanert July 23, 1957 

